An ice detector for the automatic control of iced prevention and snow melting cables used on driveways, ramps and exterior steps.Equipped with a humidity probe and temperature sensor, the ice detector is the ideal complement to the heating cables.The controller determines the optimum switch-on time so that the heating comes on in good time to prevent ice formation i.e. before the temperature reaches freezing point.Unnecessary waste of energy is avoided as the system is only switched on when there is a risk of Ice formation.